The utilization of hermetically sealed motor-compressor units has become increasingly prevalent in recent years in refrigeration applications where the motor-compressor units are employed to compress refrigerant vapor. The compressor is generally driven by an electric motor which rotates the crankshaft of the compressor at relatively high speeds. These hermetically sealed compressors are frequently located in environments where it becomes necessary to protect the connections of the electrical system and ensure that the integrity of the electrical connections is maintained. Typical electrical connections for a hermetically sealed compressor include power lines for providing electricity for operating the motor and control circuitry which monitors the operation of the compressor and which shut it down when an out of specification event is detected.
Typically one or more terminal assemblies are provided which allow electric power and/or electrical monitoring systems to extend through the shell of the compressor. The power supply terminal assemblies typically comprise a body member welded or otherwise secured to the shell of the compressor. The body member has a plurality of conductor pins which are secured to and extend through the shell such that one end of each conductor pin is located within the shell and the opposite end is located outside the shell. Electrical insulating and sealing material such as glass and/or epoxy potting forms a hermetic seal between each conductor pin and the body member. The internal end of each conductor pin is connected to the electrical leads of the motor. The external end of each conductor is connected to a suitable source of power.
In order to provide protection and sealing for the terminal assemblies, a terminal box is attached to the shell around the various terminal assemblies. The terminal box includes the appropriate cutouts to provide access to the various terminal assemblies and seals are provided around these cutouts in order to protect the terminal assemblies from the outside environment. Typically, an external connector block assembly is positioned over the power supply terminal assembly with this external connector block assembly being held in place by a cover which closes the terminal box. The external power is typically provided by a plurality of conductors which are attached to the external connector block assembly. Each of the plurality of conductors electrically engages a respective conductor pin when the external connector block assembly is assembled to the power supply terminal assembly. Once this connection is made, the terminal cover is attached to the terminal box to retain the external connector block assembly and isolate the electrical connections within the terminal box.
On the inside of the shell, an internal connector block assembly is positioned over the power supply terminal assembly. The internal connector block assembly routes electrical power from the power supply terminal assembly to the electric motor which drives the compressor. The internal connector block assembly includes a connector block and a plurality of connectors or end fittings which frictionally engage the conductor pins of the power supply terminal assembly.
One requirement for the internal connector block assembly is that its size be kept as small as possible so that it does not interfere with the other components of the compressor. When applications are encountered which require a higher current to be supplied to the motor, larger diameter conductor pins are required which in turn increase the size for the power supply terminal assembly, the external connector block assembly and the internal connector block assembly.
The present invention provides the art with an internal connector block assembly which minimizes the size of the internal connector block assembly to allow for the increase in diameter of conductor pins while still providing for a simple assembly and disassembly of the internal connector block assembly. The internal connector block assembly includes a connector body and a plurality of end fittings, each of which is attached to one or more respective wires. Each end fitting is assembled to the connector body by inserting and then rotating the end fitting to secure it within the connector body. Once assembled to the connector body, the internal connector block assembly is pushed onto the conductor pins of the power supply terminal assembly. The insertion of the conductor pin into the end fitting prohibits reverse rotation of the end fitting with respect to the connector block and thus the disassembly of the end fitting from the connector block. The present invention thus provides a low cost and minimum sized internal connector block assembly which is easily assembled to and disassembled from the power supply terminal assembly.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.